The described embodiments relate to mobile electronic devices, and in particular, to lens members associated with display units and their assembly methods.
Mobile electronic devices, such as mobile phones, pagers, handheld computers, laptop computers, etc., are becoming increasingly popular for both business and personal use. One reason for this popularity relates to the inherent portability of such devices. A user may have the device with them at all times by simply carrying the device in their pocket, bag or attached to a belt or pocket such as through a clip-on carrier. This portability, however, also requires these devices to be relatively rugged as they are often subjected to rough treatment, including dropping and scratching. Certain components of the device, such as the display unit, is very sensitive to such rugged treatment. An impact on the surface of a display unit may cause it to malfunction, or not to function at all. Similarly, a scratch on the surface of a display unit interferes with a user's ability to see what is being displayed. Being a key component relating to customer satisfaction, manufacturers try to avoid these non-desirable conditions by protecting the display unit. In order to protect the display unit, such mobile electronic devices typically employ a protective, transparent lens positioned between the surface of the display unit and the outside of the device.
Typically, a lens is one of the last components assembled onto a mobile electronic device. One reason for placing the lens in position late in the assembly process is to reduce handling, and hence the potential for nicking and scratching, of the lens during the assembly process. Another reason is that a lens may be made from different colors of transparent materials, or may include various printed designs or word/names, each of which may be utilized to meet consumer desire or manufacturer branding needs. For these reasons, among others, a lens is typically secured to the outside surface of a mobile electronic device once the entire device is assembled together. For example, an adhesive, such as an acrylic glue, or a mechanical fastener, such as a screw, may be utilized to hold the lens in place.
The placement of the lens onto the exterior of the mobile device, however, presents a number of problems. In many cases there is only an adhesive that secures the lens to the exterior of the device. The strength of such adhesives may change depending on the temperature, thereby allowing the lens to shift relative to the display unit or to fall off. Similarly, mechanical fasteners may be sheared off with the impact of dropping the device, thereby allowing the lens to loosen or fall off. Further, in some applications, such as when a mobile electronic device is desired to be secure from tampering, such as with devices carrying a warranty or with devices used in confidential applications, the exterior mounted lens allows access to the interior of the device. Typical lens mounting techniques allow a person to tamper with the device through the lens without leaving any evidence of the tampering. For example, externally secured mechanical fasteners may be removed and re-installed, or an adhesive seal may be broken by elevating or lowering the temperature and then re-sealed by bringing the device back to a room temperature. As such, typical lenses and their associated assembly methods allow a lens to become loose, to fall off, or to be tampered with without providing evidence of the tampering.
Thus, a lens for protecting a display unit of a mobile electronic device is desired to be tamper-resistant and/or tamper-evident, and which does not rely on external fixation of the lens.